Spring Rate=Rider Weight (lbs)×Rear Wheel Travel (ins)×0.65Shock Stroke (ins)2×Desired Sag (decimal)Spring Rate equals the fraction with numerator Rider Weight (lbs) cross Rear Wheel Travel (ins) cross 0.65 and denominator Shock Stroke (ins) squared cross Desired Sag (decimal) end-fraction Example Calculation: Rear Wheel Travel: Shock Stroke: Desired Sag:
: Total weight including all riding gear (helmet, shoes, hydration pack).
Because calculating dynamic rear-wheel weight distribution varies by bike geometry, suspension engineers use a highly reliable shortcut formula for modern enduro and downhill bikes: dhx2 spring calculator
Select your bike model from the dropdown menu. This automatically loads the leverage ratio curve. If your bike is not listed, you will need to manually input the Travel (mm) and Stroke (mm).
The DHX2 has specific features that interact with spring calculation differently than standard coil shocks. Spring Rate=Rider Weight (lbs)×Rear Wheel Travel (ins)×0
Note: High-end DHX2 calculators often use the Progression Curve rather than the average ratio, as many modern bikes are highly progressive (rate changes throughout the travel).
Wear your riding gear, stand up in the "attack position" on your bike, and have an assistant measure the distance between the shock mounting eyes. If your bike is not listed, you will
Turn the black spring preload collar counter-clockwise until the spring is loose. Turn it clockwise until the collar firmly touches the spring so it cannot rattle. This is zero preload .
An incorrect spring rate will drastically compromise your bike's traction, bottom-out resistance, and geometry. This comprehensive guide serves as your definitive manual and manual calculator to determine the perfect spring rate for your Fox DHX2. 1. The Core Variables Needed for Calculation